Drill-recovery tool for deep wells



J. BENSON May 6, 1924. A 1,493,233

DRILL RECOVERY TOOL FOR DEEP WELLS Filed May 12, 1923 Patented May 6, 1924.

UNITED STATES PATENT JOHN BENSON, OF WEST CHICAGO, ILLINOIS. I

DRILL-RECOVERY TOOL ron DEEP WELLS.

1 Application filed May 12,

To all whom it may concern Be it known that LJOHN BENSON, a citizen of the United States, and a resident of West Chicago, county of Du Page and State of Illinois, have invented certain new and in Drill-Recoverycovery tool.

Second. To provide simple and efficient means for manually effecting release of the drill from the recovery-tool after recovery of the drill.

Third. To provide means for initially positioning the active drill engaging elements of the recovery tool with respect to the diameter of the partof the drill to be recovered in order to effect engagement thereof with the drill at said point, and further to provide a relatively wide range of adjustment of said active elements sov as to adapt a single recovery .tool to be used for recovering tools of various sizes.-

Fourth. To provide a single element for effecting both aforesaid adjustments of the active drill engaging elements. 7

Other objects and advantages of the invention will be fully explainedrin the following specification.

The preferred embodiment of the invention is illustrated in theaccompanying drawings wherein Fig. 1 is acentrallongitudinal section of a drill recovery tool constructed in accordance with the invention.

Fig. 2 is a transverse section ofv the same .on the line-2.2 of Fig. l; and

Fig. 3 is a detailperspective flviewcf a grab expanding key employed;

Deep .welldrills are made algreat va-j riety of different designs 'w'ith respect to the shanks thereof, :the heads being. generally cylindrical and relatively'fshort- If the tool becomes detached from the drill rod or the sh nk he eofis broke he s J ller from; thcin rtllreeeyered. with the 192s. Seria1;1 Io.638,561.

drill-rod the mostv advantageous point at which to grab the remaining portion of the tool in the well. .Accordingly, by determinmg the distance between the uppermost end of the broken or detached shank of. the tool and the point at which he desires to grab the same, the well-driller can determine the distance betweenthe grabs of the tool and the upper end of the hollow or bore thereof so as to effect projection of the shank into said bore or hollow the exact distance required to eifect engagement of the grabs with that portion of the shank or head of the drill which he desires to engage. There is also some difference in diameters of the shanks of drills which the driller must take into ac-- count when endeavoring to recover the drill.

The tool of the present invention consists essentially of a shank 1 of such length and general shape as may be adapted for engagement in the end or chuck ofthe drill-rodems ployed, the lower endQ of said shank ortoolhead constituting a stop against which the upper end of the shank of the drill is adapted to abut. The lower end portion of said shank or tool-head 1 is externally threaded erably threaded externally at its upper and lower 'endportion's. The upper end portion thereof is adapted to be engaged by the internally threaded sleeve 5 which also has threaded engagement with the larger portion of said shank or tool headl.

Threaded upon the lower end portion of the pipe section 4 is the grab containing portion or grab-head 6 of the tool which is internally threaded at its upper end portion to receive said pipe section 4:, the latter being preferably held against rotation relatively thereto after being mounted thereon by tapping holes 7 into the threaded portion of the pipe section toreceive a set screw 8.

Thegrab-heztd 6 is cylindrical externally, and below the threaded portion thereof the circumferential wall thereof is preferably gradually increased in thickness to the lower end of the same, the lower edge of said wall being bevelled as indicated at 9 so as to pro- .vide a sharp outer cutting edge, said bevelled edge being also adapted to guide the extr'eme upper end of the'drill into said head 6. Between its ends, said headfi is provided internally with an annular tapered groove 10 converging toward the lower end or bevelled edge of said portion 9, the greatest depth of said groove 10, being such, with reference to the angularity of the bevel, as may be best adapted to the purpose of its use. Mounted within said bevelled groove 10 is the grab-element 11 which consists of a split ring having, preferably, a cylindrical inner face and a tapered or bevelled outer face, corresponding preferably with the bevel of the groove 10. preferably composed of steel or other suitable material having some resiliency so that it may be contracted and expanded by moving it longitudinally of the head 6, by engagement of its outer face with the opposed face or wall of the groove 10. The upper end of the pipe-section l constitutes a means for forcing said grab 11 downwardly toward the mouth of the head 6 in order to contract it to the degree necessary to elfect'engagement with that portion of the drill to be recovered which it is desired to engage. The inner cylindrical face of the grab is provided with a plurality of inwardly projecting toothed or serrated surfaces 12' which are adapted to bite into that portion of the surface of the drill-shank or head adapted to be engaged, the said teeth having their.

ed to be inserted, the smaller lateral dimension of said end portion 14; of said key being less than the width of said open space in the grab so that by inserting and rotating said key on its own axis said head 14: will act as a wedgeto efiect expansion of said grab to thereby release it from engagement with the tool.

After the serrated surfaces of the grab have engaged the tool, the weight of the latter plus the resistance to raising the same occasioned by friction or its becoming wedged in the bore of the well, will obviously tend to effect a downward movement of the grab 11 relatively to the head 6, thus effecting a further contraction of said grab 11 and a correspondingly tighter hold on the surface of the tool. The expansion of the said grab by means of the key will obviously tend to effect its upward movement relatively to the head 6 at the same time that it effects release of the serrated surfaces from the surface of the tool engaged thereby.

The length of the pipe section 4: will be determined by the distance between the stop 2 and the grab 11 which will determine the point at which the grab is adapted to engage the tool. Obviously in this way the tool Said grab ll is to facilitate its engagement with the drill point to be recovered. I

While I have shown the preferred embod ment of the invention in the drawings, it will be understood, of course, that the same ,may be varied in details of'construction to adapt it to any particular type or style of drill point to be recovered and to the particular conditions appertaining to the wcll, without departing from the invention as defined in the appended claims.

I claim as my inventioni I 1. A drill recovery tool including a grab head, an elastic one piece split ring loosely disposed within the same, grab elements as sociated with said split ring, the latter and. said head having coacting means, for efiecit ing contraction of said ring to cause sa d grab elements to engage a drill to be recovered, and .manually operable means for efffecting .forced' expansion of said ring to effect disengagement of said grab elements from the recovered drill.

2. A drill-recovery tool including a grab head, an elastic one piece split ring, grabelements carried thereby, a carrier forflsaid grab-head, a sleeve connecting the latter with said carrier and detachably' engaged with .said .head and said carrier, the lower endof the latter constituting a stop for-ma tion for limiting the projection of the drill to be recovered 'into said recovery tool to thereby determine the point between the ends of the drill to be engaged by said grabelements, the length of said sleeve determining said point, V

8. A drill-recovery tool including a h0llow grab-head, a one piece split ring'fgrab elements operatively associated therewith, a stop associated with the grab-head for determining the point in the drill to be recovered for engagement of the grab, elements therewith, and means for varyingthedistance between said grab-elements andsaid sto 4 A drill-recoverytool including a grabhead, a one piece split ring having grabs operatively associated therewith, movable longitudinally of the grab-head to thereby effect relative radial movement of said grabs, and including means for normally maintaining said grabs at. one limit of ,movement relatively to. said head, and

of the surface to be engaged by said grabs;

5. 'A drill-recovery toolinclhding a'grab-=' head, a' one piece split ring having grabs operately associated therewith, movable longitudinally of the grab-head to thereby effect relative radial movement of said grabs, and including means for normally maintaining said grabs at one limit of movement relatively to said head, means for forcibly maintaining said grabs normally disposed at any desired point between the limits of their movement relatively to the head to thereby adjust their position therein with respect to the diameter of the surface to be engaged by said' grabs, and a carrier for said grab-head, said last-named means constituting a coupling connecting said carrier with said grab head.

6. A drill-recovery tool including a grabhead, a one piece split ring having grabs operatively associated therewith, movable longitudinally of the grab-head to thereby effect relative radial movement of said grabs, and including means for normally maintaining said grabs at one limit of movement relatively to said head, means for forcibly maintaining said grabs normally disposed at any desired point between the limits of their movement relatively to the head to thereby adjust their position therein with respect to the diameter of the surface to be engaged by said grabs, and a carrier for said grab-head constituting a stop adapted to be engaged by the drill to be recovered for determining the portion of the surface thereof to be engaged by said grabs, said last-named means constituting a coupling connecting said carrier with said grabhead and further constituting means for determining the distance between said grabs and said stop.

7. A drill recovery tool including a grabhead, a one piece split ring having grabs carried thereby movable longitudinally and radially of the grab-head, and including means for normally maintaining said grabs disposed at their uppermost and outermost limits of movement relatively to said head, a sleeve adj ustably associated with said head in engaging relation to said grabs for forcibly holding the same at a predetermined point between the limits of their movement relative to the head to thereby determine their position with respectto the diameter of the surface of the drill to be engaged thereby, and a stop in the sleeve for determining the point between the ends of the drill to be recovered to be engaged by said grabs.

relative to the head to thereby determine their position with respect to the diameter of the surface of the drill to be engaged thereby, and a stop in the sleeve for determining the point between the ends of the drill to be recovered to be engaged by said.

grabs, and manually operable means for effecting release of said grabs from the recovered drill.

In testimony whereof, I have hereunto set my hand, this 9th day of May, 1923.

JOHN BENSON. 

